A pretreatment widely employed prior to the cold drawing of carbon steel tubing consists of the formation of a phosphate conversion film on the surface of the steel tubing followed by the formation of a lubricating film on the phosphate conversion film through the application of, inter alia, a metal soap solution. A problem associated with this technique is that a portion of the phosphate and metal soap adheres as scale on the surface of the steel tubing after the cold-drawing operation, and this serves to diminish the steel tubing's metallic luster.
According to Japanese Patent Application Laid Open [Kokai or Unexamined] Number 63-215797 [215,797/88], drawn steel tubing with an excellent metallic luster is obtained after a facile pretreatment by avoiding the use of a phosphate conversion treatment and metal soaps. Japanese Patent Application Laid Open Number 63-238921 [238,921/88] provides for the production of steel wire with an excellent metallic luster, although this art is not principally intended for the manufacture of steel tubing. However, further improvement is still desired with regard to such factors as the cross section reduction ratio and seizure resistance of tubing during cold drawing.